Giant cell arteritis and visual loss. A 3-year retrospective hospital investigation in a Danish county.

An ophthalmic status is given for 95 consecutive patients referred from other departments of the Central County Hospital 1986-88 due to suspected giant cell arteritis. Eventually, the diagnosis was confirmed in 51/95 (18 had positive biopsy of the temporal artery; in 33 it was on clinical grounds). Nine of the 51 had significant visual loss, in one even as bilateral blindness. Generalized malignancies were found in 2 of the 44 with diagnosis other than giant cell arteritis. Retrospectively, in the same 3-year period a total of 263 cases of giant cell arteritis were registered in the somatic hospitals of the county (population 340,000). One further case with visual loss became known from requests to the primary health sector ophthalmologists. Between 3-4% were thus known to have significant visual loss, a result mainly in keeping with other Nordic clinical studies. Probably, the low figures of visual impairment are related to high diagnostic rates of giant cell arteritis, and to early treatment. Our hospital-based data of giant cell arteritis gave a calculated annual incidence of 1 per 1000 of those older than 50 years in the county, or 27/100,000 including all ages. The true county incidence would be even higher had it been possible to find and include the additional cases of giant cell arteritis who were diagnosed and treated in the primary health sector only.